Fig 7.

Sp1-DRD is sufficient to rescue the repair defect due to Sp1 depletion. Cells stably expressing Sp1-DRD were transduced for expression of I-PpoI and shRNA-targeting Sp1. (A) Western blotting was used to assess KD and reexpression levels of endogenous Sp1 and the mutant Sp1. (B) Seventy-two hours after I-PpoI infection and Sp1 KD, cells were treated with 4-OHT, and damage was assessed by qPCR at various time points after induction, as described in the legend to Fig. 5. Data represent means and SEM from three independent experiments assessed in triplicate. Data points for Sp1 shRNA are significantly different from nontargeting shRNA and Sp1 shRNA plus Sp1-DRD, which are not significantly different from one another at 2 to 12 h after tamoxifen. P < 0.05.